DE3630611C2 - - Google Patents

Description

The invention relates to an electronic musical instrument where external acoustic signals in digital Form recorded and reproduced at desired pitches will.

Up to now, external acoustic signals have been used in practice Signals from musical instruments such as piano, violin etc. or noises such as bird sounds in digital form by means of a suitable modulation system, e.g. B. one PCM system (pulse-coded modulation) saved, after which the stored signals from a memory as sound signals of a keyboard instrument were read out.  

From DE-OS 35 28 716 and DE-OS 35 28 719 by the applicant such music is of the present invention known instruments.

From EP-A 01 24 197 an electronic music instrument is known in which digital signals representing a waveform are read from a waveform memory and are subjected to a predetermined signal processing process. The processed signals are possibly combined to form a mixed signal. The mixed signals can in turn be stored in the waveform memory 13 . In this way, a new waveform can be generated from a stored waveform, which in turn can be stored back in the waveform memory.

A disadvantage of this known device is that a certain waveform, so to speak, only with itself can be modified - a mixed signal is produced by combining two signals from one and the same Waveform - so that ultimately only one ver equally monotonous variation namely the generation a so-called "plucked string sound" is possible.

It is therefore an object of the present invention electronic musical instrument to create one rich variation of saved waveforms enables.

This problem is solved by the features of Claim 1.  

Further details, features and advantages of the present Invention result from the following Description with reference to the drawings.

It shows:

Fig. 1 is a block diagram of an embodiment of the present invention

Fig. 2 is an essential part of a keyboard / display section;

Fig. 3 schematically simplified a tone generation control unit;

Fig. 4 is a timing diagram for explaining the operation of the device according to the invention;

FIG. 5 shows the storage state of a waveform memory; and

Fig. 6 is a flow chart for explaining the device according to the invention.

Referring to FIG. 1, an input signal IN, which is supplied through a microphone or the like, amplified by an input amplifier 1 and then fed to an analog adder. 2 An output signal of the analog adder 2 is fed through a filter 3 to a sample / hold circuit 5 (Sample / Hold = S / H) and is sampled there with a suitable sampling frequency. An output signal from the circuit 5 is fed to an analog / digital converter 6 . The A / D converter 6 converts the input analog signal into a corresponding digital signal, which is then fed to a sound generation control unit 8 .

The tone generation control unit 8 has, for example, four waveform read / write channels. These read / write channels can independently access a waveform memory 7 in order to write or read waveform signals. The sound generation control unit 8 can have a structure as in the aforementioned DE-OS 35 28 719.5 and will be explained later with reference to FIG. 3.

The control unit 8 operates under the control of a CPU 9 which has a microcomputer or the like.

The tone generation control unit 8 reads digital signals corresponding to a maximum of four tones in time-division multiplexing from the waveform memory 7 via the four waveform read / write channels and supplies the digital signals read out to a digital / analog converter 10 in time-division multiplexing. The analog signals of the D / A converter 10 are supplied to sample / hold circuits (S / H) 11 a to 11 d. The S / H circuits 11 a to 11 d sample the corresponding analog signals during corresponding periods of time under the control of time signals t 1 to t 4 , which are generated by a time generator 20 . The circuits 11a to 11d cause their corresponding voltage signals held voltage controlled filters (voltage controlled filter = VCF) 12 a to 12 d. The VCFs 12 a to 12 d filter the incoming signals according to voltage signals FCV 1 to FCV 4 .

The VCFs 12a to 12 d, the filtered analog waveform signals cause the voltage controlled amplifier (voltage controlled amplifiers VCA =) 13 a to 13 d. The amplification factors of the VCAs 13 a to 13 d are controlled as a function of control voltage signals ACV 1 to ACV 4 in order to determine the output value or the envelope of the waveform signals.

The output signals of VCAs 13 a to 13 d are output as corresponding channel output signals OUT 1 to OUT 4 , which are amplified in a suitable manner and then emitted as sound. Furthermore, the output signals of VCAs 13 a to 13 d are mixed in an analog adder 14 , the output signal of which is output as a mixed output signal OUT MIX.

The output signal of the VCF 12 d corresponding to the fourth signal and the output signal of the analog adder 14 are fed to an analog switch 15 which switches under the control of the CPU 9 .

The analog switch 15 thus selects either the output signal of the VCF 12 d or the output signal from the analog adder 14 and feeds the selected signal to a further voltage-controlled amplifier (VCA) 16 . The VCA 16 amplifies the input signal as a function of a control voltage ACV 0 and couples the amplified signal back to the analog adder 2 .

Thus, an external signal, which is fed to the input amplifier 1 , and a waveform signal read from the waveform memory 7 are mixed in the analog adder 2 and stored back in the waveform memory 7 .

In Fig. 1, reference numeral 4 denotes a keyboard / display section which has keys corresponding to different musical notes and a plurality of different control switches as well as a liquid crystal display or the like for displaying various operating states of the musical instrument. The keyboard and display are connected to the CPU 9 for data transmission.

Fig. 2 shows the structure of an essential part of the key / display section 4. Tone switches 41 to 44 are provided to set four different tone numbers. The corresponding switches are associated with a 41 to 44 a in the form of light-emitting diodes to the selected switch by the note numbers indicate display elements.

The reference symbol 45 in FIG. 2 denotes a recording switch. When the recording switch 45 is actuated, a display element 45 a is illuminated. Reference symbol 46 denotes a proportioning switch to which a display element 46 a is assigned. Finally, reference numeral 47 denotes a trigger switch for generating a trigger signal, to which a display element 47 a is assigned. The operation of the switches 45 to 47 will be explained later.

The keyboard / display section 4 also has a display 48 with a liquid crystal dot matrix display. The display 48 shows the switching states of the various switches and the various operating states in plain text. In FIG. 2, an example of display is shown of a certain condition, wherein the meaning of this display will be explained later.

The CPU 9 in Fig. 1 is programmed to supply digital signals to D / A converters 17 to generate voltage signals which serve as control signals FCV 1 to FCV 4 , ACV 1 to ACV 4 and ACV 0 . (These signals are collectively referred to as control signals CV).

The group of D / A converters 17 can contain a number of individual D / A converters corresponding to the number of control signals CV or, alternatively, a single D / A converter which then generates the control signals CV using time division multiplexing.

The circuit construction of the tone generation control unit 8 will be explained in more detail below with reference to FIG. 3.

A digital signal corresponding to a waveform from the A / D converter 6 is supplied to the waveform memory 7 via a gate 81 and to the D / A converter 10 via a gate 82 . The gate 81 is controlled by a read / write signal R / which is generated by an internal control circuit 80 of the control unit 8 in response to a control command from the CPU 9 . The gate 81 is open when a waveform signal is written in the waveform memory 7 . The gate 81 is closed when a waveform signal is read out from the waveform memory 7 . The gate 81 is controlled by a signal obtained by inverting the read / write signal R /.

The gate 82 receives a gate signal GATE, which is generated by a gate signal generator 83 in response to a control signal from the control circuit 80 . The gate 82 is only turned on when a digital signal is output from the gate 81 or a digital signal is output from the waveform memory 7 .

In Fig. 3, reference numeral 84 denotes an address shift register with four stages (corresponding to the four channels), each stage consisting of a fixed number of bits. The shifting process of the address shift register 84 is determined by a main clock ⌀ _s , which will be described later and is generated by the time generator 20 . The address shift register 84 operates as a 4-channel address register in time division multiplexing. Data in its last stage is supplied to the waveform memory 7 as address data. When the read / write signal R / is low, a waveform signal passed through the gate 81 is written in the memory area specified by the address data. If the signal R / has a high logic value, a digital signal is read out of this memory area. The data of the address shift register 84 are supplied to a gate 85 , the gate signal generator 83 and the control circuit 80 . The address signal is fed through gate 85 to an adder 86 which performs addition or subtraction for re-addressing. The output of adder 86 is fed back to address register 84 . A start address CA is supplied from the control circuit 80 to the adder 86 via a gate 87 .

More specifically, a charge signal is fed directly to gate 85 and continues to gate 87 via an inverter 88 . When the load signal is low, the start address CA is supplied from the control circuit 80 through the gate 87 to the adder 86 . When the load signal is high, gate 85 is turned on and the data in the last stage of address shift register 84 is applied to adder 86 .

A clock signal CK is supplied to the adder 86 from a clock generator 89 . When a digital signal having a pitch frequency is read out from the waveform memory 7 , a clock signal is supplied to the adder from the control circuit 80 at a rate corresponding to the pitch date. When digital data is read in the waveform memory 7 , a clock signal is generated at a rate corresponding to the sampling frequency to perform address renewal. The operation of the previously described embodiment will now be described below.

Fig. 4 shows a timing diagram of the time-division multiplexing method for the individual channels of the tone generation control unit 8 and the time signals t 1 to t 4 , which are supplied to the S / H circuits 11 a and 11 d. As already mentioned, in this embodiment the four waveform read / write channels are implemented by a time-division multiplex circuit and either the read or write process is selected and independently for each waveform read / write channel. In the example of FIG. 4 (B), in the case of channel 1 (ch 1 ), a waveform signal obtained through the filter 3 , the S / H circuit 5 and the A / D converter 6 is converted into the Waveform memory 7 written, while in the case of the other channels 2 to 4 (ch 2 to ch 4 ) digital waveform signals from certain areas of the waveform memory 7 are read out.

The time signals t 1 to t 4 according to FIGS. 4 (C) to 4 (F) are logically high during the time periods corresponding to the respective channels (ch 1 to ch 4 ). During these corresponding channel times, analog waveform signals are sampled and held by the D / A converter 10 in the S / H circuits 11 a to 11 d.

Fig. 5 shows separate regions of the waveform memory 7. For example, N different waveform signals with variable lengths can be stored. Each waveform read / write channel of the tone generation control unit 8 can independently select a read / write memory area. For example, in the case of channels 2 to 4, sound data 1 to 3 according to FIG. 5 are read out and via VCFs 12 b to 12 d, VCAs 13 b to 13 d, analog adder 14 , switch 15 and VCA 16 fed to the analog adder 2 and then mixed with an external audio signal if necessary. The output signal of the adder 2 is stored in the waveform memory 7 as tone data N in accordance with the processing for channel 1 . It should be noted here that it is possible to achieve an admixing effect.

Furthermore, it is possible that the CPU 9 to the analog switch 15 switches, d to a signal read out in accordance with the processing of the channel 4 from the waveform memory 7 waveform signal via the S / H circuit 11, VCF 12d and VCA 16 to analog -Adder 2 feeds there to mix it with an external sound signal before it is written in a defined area of the waveform memory 7 in the manner described above.

In the following, the workflow mainly performed by the CPU 9 in the admixing mode will be explained in more detail with reference to the flow chart of FIG. 6.

The admixing mode is selected by actuating the switch 46 on the keyboard / display section 4 . In a step S 1 , the CPU 9 checks whether a key or switch has been actuated on the keyboard / display section 4 and determines a waveform signal which is to be read from the waveform memory 7 and the associated note pitch.

In this embodiment, the amount of sound to be generated is selected by a corresponding game key on the keyboard. The waveform signal in the waveform memory 7 is read out at a high readout rate when a high pitch has been selected and is read out at a low readout rate when a low pitch has been selected. In other words, the pitch date supplied to the clock generator 89 corresponds to the selected note.

If it has been recognized in step S 1 that a key input is present, the decision "YES" is made and the program goes to step S 2 . In step S 2, the CPU 9 stores the number of sound data, the sound data to be read out from the waveform memory 7 as selected by the keyboard / display section 4 . The CPU 9 also stores the note selected by pressing the key. Furthermore, the CPU 9 stores data for determining a corresponding sound volume. The sound volume is set by pressing buttons and volume / volume switches on display section 4 . The program then continues to step S 3 .

For example, the tone switch 42 is operated to select the tone 2 , so that the display element 42 a flashes. Thereafter, a key corresponding to the note C 3 # on the keyboard is operated and the sound volume is set to a value "56" by the volume setting device.

In step S 3 , the sound number is visually represented by the display element 42 a, the note C 3 # and the sound volume "56" by the display unit 48 . Fig. 2 shows such a state of the display unit 48.

The program then goes to a step S 4 , in which it is checked whether the trigger switch 47 is switched on. If the trigger switch 47 is not turned on, the program goes back to step S 1 . In the event that the tone switch 43 has been actuated to select the tone 3 , the key of the note C 4 # on the keyboard is actuated, the tone volume is set to a value "50" and a corresponding display takes place through the steps S 2 and S 3 .

If it has been selected at this time on the keyboard a different note, while the same tone number is set, this state is determined by the display elements 41 a to 44 a, and the display unit 48 shown.

Finally, stored digital signals and - if available - externally supplied signals are combined to select a tone number to be replaced. In the example described above, when the tone switch 44 is operated while the recording switch 45 is operated, the sound of the tone 2 with the pitch of the note C 3 # and the volume level "56" is generated and the waveform signals of the tones 2 and 3 become synthesized and recorded as sound 4 in the waveform memory 7 . At the time of actuation of the recording switch 45 , the display elements 42 a and 43 a are switched on and the display element 44 a flashes, so that the tone number of the reproduced tone and the tone number of the recorded tone are displayed.

Step S 4 is also carried out if the decision in step S 1 is "NO". In step S 4 it is checked whether a trigger signal for starting a current recording process is supplied by the keyboard / display section 4 . If there is no trigger signal yet, the program goes back to step S 1 . As a result, steps S 1 and S 4 or steps S 1 to S 4 are repeatedly carried out in a standby state.

When multiple keys on the keyboard are pressed, up to three different notes can be assigned to channels 2-4 . If different tone numbers are selected in the individual channels, waveform signals of different tones are reproduced with the selected notes. If the same tone number has been selected in the different channels, a waveform signal of the same timbre with different selected pitches is generated. The generated signals are then mixed together with different sound volumes.

If it is recognized in step S 4 that a trigger input signal is generated by the trigger switch 47 , the program goes to a step S 5 . It can also be provided that a trigger input signal is supplied to the CPU 9 so that the program automatically goes to step S 5 when the input signal IN exceeds a predetermined value.

In step S 5 , the CPU 9 supplies the received tone number and the grade data to the tone generation control unit 8 and selects the area and grade of the waveform data which is read out from the waveform memory 7 into the individual waveform read / write channel.

In a subsequent step S 6, the CPU 9 supplies the group 17 of D / A converters with digital signals for generating the control signals in accordance with the values set in the keyboard / display section 4 . The control signals CV are thus generated and supplied to the VCFs 12 a to 12 d, the VCAs 13 a to 13 d and the VCA 16 .

Furthermore, the CPU 9 supplies a switching signal to the analog switch 15 so that the mixed waveform signal from the adder 14 is supplied to the VCA 16 . Thereafter, the program goes to a step S 7 , in which the CPU 9 starts the recording process using the channel 1 . At this point in time, the channels selected from channels 2-4 are activated in order to read out waveform data of already defined acoustic signals from waveform memory 7 .

When the input process is over, an end state is brought about, after which the CPU 9 returns to its main program (not shown).

As described, the illustrated embodiment has the tone generation control unit 8 having four waveform read / write channels for independently reading and writing waveform signals, the same digital signal or different digital signals being read out from the waveform memory via at least two channels, that is or the read waveform signals via the VCFs 12 a to 12 d and VCAs 13 a to 13 d receive independent tones and tone volumes, after which the signals are mixed and written back as a new tone signal in the waveform memory 7 using a specific channel. It is thus possible to easily obtain the mixing function with interesting musical effects.

In addition, waveform data can be read out from the waveform memory 7 using a maximum of three of the four waveform read / write channels, after which these reproduced waveform data can be combined with the input waveform signal IN, if necessary, to generate tone waveform data. It is thus possible to obtain different types of admixture.

The waveform memory 7 may be divided into a plurality of areas, and a waveform signal obtained by the mixing operation may be written in a memory area different from the memory area in which the original waveform signal is recorded. It is thus possible to obtain an admixing process without deleting the original waveform signal.

For the waveform signals, which are read by the plurality of waveform read / write channels of the waveform memory 7, the volume value 13 may be a set d to 13 independently using the VCAs.

The same waveform data can be read out at different pitches, and the resultant data can be combined in the same memory area by a plurality of waveform read / write channels, wherein the mixing ratio is varied d on the VCAs 13a to. 13

In the described embodiment, the tone number, note and tone volume are represented by the display elements 41 a to 44 a and the display unit 48 , so that the admixing process is clear and the operation is improved.

The timbre and volume are controlled by VCFs 12 a to 12 d and VCAs 13 a to 13 d. However, it is also possible to use digital filters or digital multipliers to control the timbre, tone volume, envelope curve, etc. Furthermore, the waveform signal can also be processed differently. Finally, a system other than a PCM system can also be used as modulation to digitize the waveform signal.

The tone generation control unit 8 has a plurality of waveform read / write channels which operate in time-division multiplexing. However, it is also possible to use a plurality of channels for each channel using hardware of the same circuit structure that is separate from one another.

Furthermore, certain channels from the plurality of channels can only be write channels for writing waveform signals in the waveform memory 7 , while the other channels can be exclusively read channels for reading out waveform signals from the waveform memory 7 . The "waveform read / write channel" according to the present invention means a channel that can read as well as write or read only and write only.

In the described embodiment, the tone number of the tone to be mixed is displayed by the display elements 41 a and 44 a, which are separate from the display unit 48 . Of course, it is possible to display such data in a single display unit.

Finally, in the described embodiment only the sound volume is displayed; however, it is also possible To provide ads related to timbre, e.g. B. a filter cutoff frequency, what a player of the Musical instrument can be beneficial.

In summary, it is possible according to the invention to use a Mixing device for an electronic musical instrument create which is easy to use, high effectiveness and made interesting musical effects possible.

Claims (12)

1. Electronic musical instrument in which external acoustic signals are recorded in digital form and reproduced at desired pitches, in which waveform signals in the form of digital signals are stored in a waveform memory ( 7 ) and in which the digital signals stored in the waveform memory ( 7 ) are converted into sound signals with a selected pitch,
having a read / write device ( 8 ) for reading out digital signals representing a plurality of waveforms from the waveform memory ( 7 ) and for writing digital signals representing a waveform into the waveform memory ( 7 ),
with processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) which process a plurality of waveform signals independently of one another in accordance with a predetermined signal processing process,
with a synthesis device ( 14 ) connected to the processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) for mixing the various processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) signals obtained to produce a mixed waveform signal, and
with means ( 15, 16, 2, 3, 5, 6 ) for supplying a waveform signal derived from the mixed waveform signal to the read / write device ( 8 ) which writes this derived waveform signal into the waveform memory ( 7 ). 2. Electronic musical instrument according to claim 1, characterized in that the read / write device ( 8 ) has a plurality of waveform write / read channels. 3. Electronic musical instrument according to claim 2, characterized in that the processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) circuits with voltage-controlled filters ( 12 a- 12 d) and voltage-controlled amplifiers ( 13 a- 13 d), which are each assigned to the corresponding waveform read / write channels, and wherein the digital signals read out after conversion into an analog signal are supplied to the circuits for each channel in order to carry out an independent tone color and volume control before the signals are fed to the synthesizing device ( 14 ). 4. Electronic musical instrument according to claim 2, characterized in that at least two of the waveform read / write channels of the read / write device ( 8 ) are suitable, digital signals representing the same waveform stored in the waveform memory ( 7 ) with read different note frequencies. 5. Electronic musical instrument according to claim 2, characterized by a display device ( 4 ) for displaying a plurality of switching states which correspond to the digital signals read out from the waveform memory ( 7 ) via at least two of the waveform write / read channels. 6. Electronic musical instrument according to claim 5, characterized in that the display device ( 4 ) displays the signal processing process which is carried out to control the timbre and volume of the analog waveform signals generated from the read digital signals. 7. Electronic musical instrument according to claim 5, characterized in that the display device ( 4 ) displays the pitch at which the digital signals from the waveform memory ( 7 ) are read out via the waveform write / read channels. 8. Electronic musical instrument according to claim 1 or 2, characterized by a sampling device ( 2 , 5 ) for receiving an input signal and for sampling this input signal with a predetermined sampling frequency. 9. Electronic musical instrument according to claim 8, characterized by a control device ( 9, 15 ) for supplying the mixed waveform signal from the synthesizing device ( 14 ) to the scanning device ( 2, 5 ), after which the mixed wave form signal after conversion into a digital Signal is written into the waveform memory ( 7 ). 10. Electronic musical instrument according to claim 8 or 9, characterized in that the scanning device ( 2, 5 ) comprises:
an analog adder ( 2 ) for adding an input waveform signal and an analog signal derived from at least one digital waveform signal read out from the waveform memory ( 7 ), and
a device ( 5 ) for sampling an analog sum signal from the analog adding device ( 2 ) with a predetermined sampling frequency. 11. Electronic musical instrument according to claim 1, characterized in that the processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) voltage-controlled amplifier ( 13 a- 13 d) for controlling the level of analog Signals which are generated from the digital signals read out from the waveform memory ( 7 ). 12. Electronic musical instrument according to claim 1, characterized in that the individual processing devices ( 9, 11 a- 11 d, 12 a- 12 d, 13 a- 13 d) each selectively a characteristic parameter of the read digital signals in a predetermined Change wise.